Recent content by tech99

Maxwell noticed that emu and esu units of the cgs system used at that time are related by a constant, which he thought might be c. And it was. He tried to set up an experiment to balance the forces of electric attraction between fixed charges and the magnetic force between currents and he...

I think I am right in saying that Maxwell noticed that the electric attraction between two stationary charges is the same as the magnetic repulsion when their relative speed is that of light. Maybe someone can correct me.

I would have thought that a current is the movement of charges. There are no charges in a vacuum.

I am not certain in my own mind if a displacement current is flowing in the case of a radio wave.

I think that when you refer to the near field you are referring to the near radiation field (the Fresnel Region), and not the reactive near field. It is important to use exact terms for this or we will be at cross purposes. [see for instance the following link...

I can maybe imagine using a sum of spherical waves but not plane waves. The near field you mention is more accurately called the reactive near field. It stores energy each half cycle and returns it to the antenna the next. So in my mind I cannot visualise the field extending to infinity, or the...

The mechanism of radiation cannot be explained using the properties of the fields alone. A capacitor which has a vacuum as its dielectric will not radiate, only the wires leading to it will do that. To understand radiation we need to consider charges, such as electrons, which are subject to...

The link provided says the following: "electromagnetic waves-in which an electric field and magnetic field alternately appear-are created in the space between the two electrodes and travel into their surroundings." However, the magnetic and electric waves are in-phase, which is in conflict with...

For the sound of the machines to add in amplitude will require them to be in-phase. Even if the machines rotate together, they are still located in different positions, so that the distance from the observer to each machine will be different. This means that the sound from the machines will add...

Every wire has inductance, so the opened out conductors have L and C and still have resonances. The only requirement for an electric circuit to be a good antenna is for it to be comparable in size with the wavelength. Very small circuits do not radiate very much. There is no requirement for...

If the two waves are to be a single quasi-particle, that seems to imply that they travel at the same speed.

I feel that some of the energy of the wave when in the medium is being carried by the motion of electrons and their accompanying fields.

Some of the energy incident on the boundary is reflected, so the refracted energy is less than the incident energy. In quantum terms I suppose we say that occasional photons are reflected at the boundary.

Part of the incident energy is reflected when a wave strikes a transparent medium, so I presume that in quantum terms an occasional photon is reflected at the surface?

Is the modulation index set to a suitable level? Do you have an isolator after the laser?